The specific aims of this proposal are to develop and test a multifactorial model of work disability related to carpal tunnel syndrome (CTS), and entrapment of the median nerve at the wrist. CTS is associated with occupational ergonomic factors in addition to non-work related etiological factors. The primary hypothesis posed in this study is that occupation is also associated with the risk of work disability after onset of CTS, in a predictive model that includes medical severity, demographics, and other disability risk factors. The model predicts that work disability will be associated with ergonomic job hazards such as work tasks requiring forceful and repetitive motion, high psychological workload, low control over job-related decisions, and poor supervisory relationships. Methods: Initially, a predictive models of work disability from CTS will be developed using a secondary analysis of data from the National Health Interview Survey Occupational Health Supplement (NHIS-OHS). The model will then be tested on a CTS patient panel (n=225) garnered using a community case identification strategy developed and field tested as part of a NIOSH CT surveillance project. Disability is defined as lost work time, changes in job or job activities, and complete withdrawal from the labor force. The predictors of work disability in the model will include occupational (work task ergonomics, decision control, psychological work load, supervisor support and conflict, industry), medical severity (symptom severity, bilaterality, nocturnal symptoms, muscle wasting, surgery, co-morbidity), psychosocial (fear of reinjury, self-efficacy for pain control, family cohesion), and demographic (age, gender, ethnicity, education) factors. Panel subjects will be interviewed at baseline and annually for two years to obtain cross-sectional and longitudinal data. Relationships between the predictor variables and the disability outcomes will be analyzed cross-sectionally using multiple logistic regression and longitudinally using the Cox proportional hazards models. Long term objectives: Statistically and clinically significant occupational and individual risk factors for work disability will be identified in this study. Findings, together with those from other investigations, will contribute to the design of worksite interventions to reduce disability from cumulative trauma disorders.